KR20140115090A

KR20140115090A - Release composition having superior release properties

Info

Publication number: KR20140115090A
Application number: KR1020130029714A
Authority: KR
Inventors: 김순학; 배영민; 김영진; 곽기섭; 김효진
Original assignee: 주식회사 엔트코리아
Priority date: 2013-03-20
Filing date: 2013-03-20
Publication date: 2014-09-30

Abstract

The present invention relates to an ethylene-propylene rubber (EPM), an ethylene-propylene rubber (EPM), an ethylene-propylene rubber (EPM), a styrene- butadiene rubber (SBR), a butadiene rubber (BR), a nitrile rubber (NBR), a chloroprene rubber 100 parts by weight of at least one polymer rubber selected from the group consisting of diene rubber (EPDM), and polyisoprene rubber (NB); Based on 100 parts by weight of the polymer rubber, 30 to 50 parts by weight of a release agent; 50 to 150 parts by weight of an inorganic filler; 1 to 5 parts by weight of a detergent; And 1 to 10 parts by weight of a crosslinking agent, wherein a minimum torque value measured by ODR (Oscillating Disk Rheometer) is 0 to 30 lbf.in, and a maximum torque value is 15 to 120 lbf.in Disclosed is a rubber composition for releasing having excellent releasability. The release-use rubber composition according to the present invention does not generate odor and haze, and has good mold spreadability and deformation, thereby more effectively releasing the mold.

Description

TECHNICAL FIELD [0001] The present invention relates to a releasing rubber composition having excellent releasability,

TECHNICAL FIELD The present invention relates to a releasing rubber composition, and more particularly, to a releasing rubber composition which can effectively clean the surface of a mold by curing it in a semiconductor mold and has excellent releasability, which provides an effective mold releasing property of a molded product.

Semiconductor devices such as transistors, integrated circuits (IC), high density integrated circuits (LSI), etc. are typically resin-encapsulated by plastic packaging. Such resin encapsulation is carried out by using a thermosetting resin composition such as an epoxy resin composition or the like, and performing casting, compression molding, injection molding, transfer molding, especially mass transfer productivity with excellent productivity and workability.

However, the above-described transfer molding is carried out continuously when the semiconductor element is resin-encapsulated by transfer molding using an epoxy resin composition so that the molding die or the mold is contaminated by a mold releasing agent in the epoxy resin composition , Resulting in poor molding. That is, the mold releasing agent contained in the epoxy resin composition flows out from the resin composition to the inner surface of the cavity formed by the upper mold and the lower mold to cause the mold-releasing action. However, when the molding is repeated, I am gradually deteriorated by internal accumulation and oxidation, forming a hard oxidized mold-release agent layer (the layer surface is not as smooth as the inner surface of the mold). In addition, the molding is performed on the surface of the oxidized and deteriorated mold-release agent layer, whereby the surface pattern of the oxidized and deteriorated mold-release agent layer is transferred to the surface of the molded article, and the surface of the molded article becomes rough and uneven .

When the oxidized and deteriorated mold-release agent layer is once formed on the inner surface of the mold at the time of molding, the epoxy resin composition and further the mold-release agent are not oxidized and deteriorated from the resin composition to the surface of the mold, Layer, whereby the mold-releasing agent can not sufficiently provide the mold-releasing action.

Therefore, a cleaning operation to remove contaminants remaining in the semiconductor mold is required from time to time to form a high-quality product, and a release agent is coated on the surface of the mold in order to facilitate detachment of the thermosetting resin by repeated operation.

Such a cleaning and releasing process is indispensable, and its importance becomes more important as semiconductor devices become more highly integrated. In particular, the mold release process directly affects the quality of the semiconductor device. If the mold releasing property is not properly performed on the surface of the mold, it takes much time to repair the product as well as the entire product. Therefore, Are being developed in tandem with the high integration of semiconductor devices.

Conventionally, a method of periodically cleaning by manual or air jetting in order to remove contaminants around the cavity of the mold is used, or a method of immersing the mold itself in a cleaning liquid and cleaning is performed. However, these methods are time consuming and troublesome.

As another method of mold cleaning, a method of cleaning using a melamine resin or a rubber sheet is widely used. This is a method in which a cleaning melamine resin or a rubber sheet is charged into a mold and heated and pressurized in the same manner as the product molding process.

However, in the case of washing with melamine resin, there is a problem in that the cleansing property is lowered and formalin generation occurs as a result of curing. In the case of a rubber sheet, cleaning property is superior to melamine resin, but cleansing component is cured at a high temperature of 150 to 180 ° C, So that there is a problem that smoke or smoke is generated and the environment of the worker is deteriorated.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a release-type rubber composition excellent in releasability, which prevents secondary fouling of a semiconductor mold by improving releasability without generating any smoke or mist.

According to an aspect of the present invention,

Butadiene rubber (BR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene terpolymer rubber (EPT), ethylene-propylene rubber (EPM), ethylene- EPDM), and polyisoprene rubber (NB); Based on 100 parts by weight of the polymer rubber, 30 to 50 parts by weight of a release agent; 50 to 150 parts by weight of an inorganic filler; 1 to 5 parts by weight of a detergent; And 1 to 10 parts by weight of a crosslinking agent. The present invention relates to a releasing rubber composition having excellent releasability.

Also, preferably, the release rubber composition has a minimum torque value measured by an ODR (Oscillating Disk Rheometer) of 0 to 30 lbf.in.

Also, preferably, the release rubber composition has a maximum torque value measured by an ODR (Oscillating Disk Rheometer) of 15 to 120 lbf.in.

Preferably, the releasing agent is at least one selected from synthetic wax (FT), polyethylene wax (PE), polytetrafluoroethylene wax (PTFE), combination wax, fatty acid amide wax, vegetable wax, animal wax and mineral wax .

Also preferably, the inorganic filler is selected from silica, silica gel, carbon black, calcium carbonate, calcium silicate, zirconium, iron oxide, activated alumina, aluminum hydroxide, titanium oxide, titanium hydroxide, amorphous aluminosilicate and crystalline aluminosilicate Or more.

Also preferably, the cross-linking agent is selected from the group consisting of dt-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis- (t-butylperoxy) ). &Lt; / RTI >

It is also preferable that 1 to 8 parts by weight of an additive which is at least one selected from stearic acid, titanium dioxide, antioxidant and silane is contained.

According to the present invention, the release-type rubber composition having excellent releasability does not generate a waste smoke or mist as it is cured and provides effective releasing property while giving continuous coating performance to the inside of the mold, thereby providing excellent semiconductor resin-encapsulation workability and preventing environmental pollution can do.

Hereinafter, the present invention will be described in detail.

The present invention relates to an ethylene-propylene rubber (EPM), an ethylene-propylene rubber (EPM), an ethylene-propylene rubber (EPM), a styrene- butadiene rubber (SBR), a butadiene rubber (BR), a nitrile rubber (NBR), a chloroprene rubber 100 parts by weight of at least one polymer rubber selected from the group consisting of diene rubber (EPDM), and polyisoprene rubber (NB); Based on 100 parts by weight of the polymer rubber, 30 to 50 parts by weight of a release agent; 50 to 150 parts by weight of an inorganic filler; 1 to 5 parts by weight of a detergent; And 1 to 10 parts by weight of a crosslinking agent. The present invention relates to a releasing rubber composition having excellent releasability.

Hereinafter, each composition will be described in more detail.

The polymer rubber used in the present invention is natural or artificial rubber. When the inside of the mold receives heat and pressure during the cleaning process, the polymer rubber component flows in the mold and penetrates into the fine structure, and is molded into a mold shape, The polymer rubber is used to facilitate contaminants during the cleaning process. The polymer rubber should be flowed and filled in a shape exactly matching the inside of the mold, so that the releasing agent component described later flows to the outside, . Therefore, the polymer rubber used in the present invention must be able to have an accurate shape inside the semiconductor mold, and the release of the release agent components should be easy.

Examples of such a polymer rubber component include styrene-butadiene rubber (SBR), butadiene rubber (BR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene terpolymer rubber (EPT), ethylene- Ethylene-propylene diene rubber (EPDM), and polyisoprene rubber (NB), or a mixture thereof. In one embodiment of the present invention, a mixed rubber of butadiene rubber (BR) and ethylene-propylene diene rubber (EPDM) was used.

In the present invention, the releasing agent is a material which is blended with the polymer rubber component and is dissolved in the semiconductor mold as the polymer rubber component is cured to form a coating film in the mold, and the releasing agent should be mixed in an appropriate amount. Accordingly, in the present invention, the release agent is preferably contained in an amount of 30 to 50 parts by weight based on 100 parts by weight of the polymer rubber. When the amount of the releasing agent component is less than 30 parts by weight, the releasing agent component to be eluted during the curing of the polymer rubber is not sufficient and sufficient mold-releasing performance can not be obtained due to insufficient coating in the mold. When the amount exceeds 50 parts by weight, The curing of the polymer rubber takes a long time and the strength of the polymer rubber is lowered to break easily, resulting in chip out in a fine portion inside the mold, which may cause defects in the manufacture of semiconductors. In addition, some of them become self-carbonized and become pollution sources.

More specifically, the releasing agent may be at least one selected from synthetic wax (FT), polyethylene wax (PE), polytetrafluoroethylene wax (PTFE), combination wax, fatty acid amide wax, vegetable wax, animal wax and mineral wax Mixture. In addition to the wax component, a silicone oil may be further added as the releasing agent to increase the degree of grafting with the rubber and improve the coating property by the silicone oil.

The inorganic filler used in the present invention is an inorganic filler generally used for controlling the hardness of rubber compounding. It prevents local stress due to the characteristics of the semiconductor mold and enhances the cleaning performance by using it as a fine powder in consideration of fluidity and reliability. The releasability of the mold can be improved.

The content of the inorganic filler may be in the range of 50 to 150 parts by weight based on 100 parts by weight of the polymer rubber. When the content of the inorganic filler is less than 50 parts by weight, the thermal expansion of the rubber itself is increased and the physical properties such as heat resistance, crack resistance and moisture resistance of the cured rubber itself decrease. When the content is more than 150 parts by weight, Molding is difficult to be performed, and a phenomenon of crumbling occurs, which is not preferable.

Specifically, the inorganic filler is selected from the group consisting of silica, silica gel, carbon black, calcium carbonate, calcium silicate, zirconium, iron oxide, activated alumina, aluminum hydroxide, titanium oxide and titanium hydroxide, amorphous aluminosilicate and crystalline aluminosilicate Or more.

Examples of the amorphous aluminosilicate include diatomaceous earth, kaolin and clay. Examples of the crystalline aluminosilicate include about 34 kinds of natural zeolite and about 100 kinds of synthetic zeolite. Specific examples of natural zeolites include, but are not limited to, Analcime, chabaxite, Gmelinite, Epistilbite, Heulandite, Stilibite, Edingtonite Specific examples of the synthetic zeolite include zeolite (zeolite), zeolite (zeolite), zeolite zeolite, zeolite zeolite, zeolite zeolite, zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite zeolite A, zeolite L, zeolite T, zeolite KG, zeolite ZK-5, zeolite X, zeolite Y, zeolite ZSM-5, zeolite D, zeolite S, zeolite R, zeolite P, zeolite Z-21 and zeolite S.

Also, the cleaning agent used in the present invention is a substance that acts to separate contaminants in the mold from the mold, and is mixed with the inorganic filler in the rubber. Generally, the detergent may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the polymer rubber.

Representative examples of such detergents include glycol ethers, esters, ketones, amines, aminoalcohols, pyrrole, imidazoles and imidazoline detergents, and may be used in combination with one or more of them.

Examples of the glycol ether cleansing agent include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, diethylene glycol monopropyl ether, Diethylene glycol monobutyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether and ethylene glycol monobutyl ether, and may be used in combination with one or more of them have.

Examples of the ester cleansing agent include ethyl formate, propyl formate, isobutyl formate, methyl acetate, ethyl acetate, methyl propionate and ethyl propionate.

Examples of the ketone cleaning agent include acetone and methyl ethyl ketone.

Examples of imidazolidine detergents are 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole and 2,4- 6 [2'-methylimidazolyl- (1) '] ethyl-s-triadine, and may be used in one or more combinations.

Examples of imidazoline cleansing agents are 2-methylimidazoline, 2-methyl-4-ethylimidazoline, 2-phenylimidazoline, 1-benzyl- Methyl-5-hydroxymethylimidazoline, 2,4-diamino-6 [2'-methylimidazolinyl- (1) Methyl-4'-imidazolinyl- (1) '] ethyl-s-triazine, 1-cyanoethyl-2-methylimidazoline and 1-cyanoethyl- Ethyl imidazoline, and may be used in one or more combinations.

Examples of the amine cleansing agent include 2-aminoethanol, 2- (2-aminoethoxy) ethanol, monoethanolamine, diethanolamine, 2-amino- (Hydroxymethyl) -1,3-propanediol, 2-amino-4-hydroxy-6-methylpyrimidine, 2- (2- aminoethylamino) Triethanolamine hydrochloride, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino- Ether, 2-aminophenol, 4-methyl-1,2,4, -triazolin-3,5-dione, 2- (dibutylamino) -ethanol, 2- , &Lt; / RTI > and combinations thereof.

Representative examples of the aminoalcohol cleaning agent include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N, N-dimethylethanolamine, N, N-dibutylethanolamine, N, N-diethanolamine, 2-amino-2-methylpropanol, 3-aminopropanol and 2-aminopropanol, and the like, and may be used in combination of one or more.

In the rubber composition of the present invention, a crosslinking agent serving as a catalyst for forming a rubber cured product by causing a crosslinking reaction between rubber molecular chains when heat is applied to the rubber composition is added. Representative examples of such cross-linking agents include, but are not limited to, dt-butylperoxide, t-butylcumylperoxide, dicumylperoxide, 2,5-dimethyl-2,5-bis- (t-butylperoxy) ), And the content of the crosslinking agent is preferably 1 to 10 parts by weight based on 100 parts by weight of the polymer rubber.

In the present invention, it may further comprise an additive depending on other uses. Inside the rubber composition, stearic acid may be included as a lubricant in order to lower mechanical friction and promote sliding, and titanium dioxide may be included as a colorant. Further, additives such as an antioxidant and silane can be used. When these additives are added to the rubber composition, the content is preferably 1 to 8 parts by weight based on 100 parts by weight of the polymer rubber.

According to the composition as described above, it is possible to produce a release-type rubber composition excellent in cleansing performance and work efficiency, and excellent in releasability that does not generate aeration smoke and fogging.

The rubber composition for releasing excellent releasability according to the present invention is a rubber composition sample put into the apparatus using ODR (Oscillating Disk Rheometer) at a curing temperature in the range of 150 to 200 캜, and the torque is measured as a function of time. The rubber composition sample provides resistance to the pendulum disk and results in a spike in torque. As the rubber composition sample is warmed to the curing temperature, the rubber composition sample becomes softer and the torque decreases. The rubber composition sample then begins to cure, which appears as an increase in torque.

In this specification, the point at which the rubber composition sample starts curing is defined as a minimum torque (ML value). This minimum torque value means the deformation characteristic and minimum viscosity of the uncured state. Further, as the hardening progresses, the torque continues to increase until the maximum value is reached. This maximum value is defined as maximum torque (MH value). This maximum torque value means the strength or shear number of the fully cured state.

The release rubber composition of the present invention has a minimum torque value ranging from 0 to 30 lbf.in. When the minimum torque value of the rubber composition exceeds the above-mentioned range, it is difficult to impart effective releasability because the rubber composition is hardly spread in the mold and hardening occurs, which is not preferable.

Also, the maximum torque value of the present invention ranges from 15 to 120 lbf.in. When the maximum torque value of the rubber composition is less than 15 lbf.in, the strength of the rubber composition is low, which may cause sticking phenomenon when the contaminant is contained in the mold, and thus the maximum torque value is not more than 120 lbf. in, the strength of the rubber composition after curing is too high, which may cause a phenomenon of rubbing of the rubber composition, which is not preferable.

The time at which the bridge reaches 10% of the maximum torque at the minimum torque is referred to as T10, and the time at which 90% of the maximum torque at the minimum torque is reached is referred to as T90. Here, the larger the T90 value, the longer the curing time for the rubber composition. The T10 according to the present invention is preferably 10 to 80 seconds, and the T90 is preferably 230 to 280 seconds. The rubber composition obtained at the completion of the cleaning process can be effectively releasable to the mold after complete curing by maintaining the shape of the mold for a predetermined time under curing conditions such as a sufficiently increased temperature for a sufficient time.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the examples.

Example

&Lt; Example 1 >

To 100 grams of a polymer rubber component containing 80 grams of BR and 20 grams of EPDM were added 40 grams of a release agent component comprising 25 grams of PE wax, 5 grams of amide wax and 5 grams of vegetable wax, 35 grams of silica B-type, 75 grams of Zeolite A and 20 grams of Zeolite Y 130 g of a filler, 3 g of an amine cleanser, 2 g of butyl peroxide as a crosslinking agent and 1 g of stearic acid and 5 g of titanium dioxide were added and dispersed to prepare a releasing rubber composition.

&Lt; Example 2 >

To 100 g of a polymer rubber component containing 80 g of BR and 20 g of EPDM was added 33.4 g of a release agent component comprising 25 g of PE wax and 8.4 g of amide wax, 25 g of silica A-type, 30 g of silica B-type and 35.5 g of zeolite Y 85.5 g of an inorganic filler, 3.3 g of an amine cleanser, 9 g of butyl peroxide as a crosslinking agent, and 1 g of stearic acid and 1 g of silane were added and dispersed to prepare a releasing rubber composition.

&Lt; Example 3 >

To 100 grams of a polymer rubber component containing 80 grams of BR and 20 grams of EPDM was added a solution comprising 40 grams of a release agent component comprising 25 grams of PE wax, 10 grams of amide wax and 5 grams of vegetable wax, 10 grams of silica B-type, 75 grams of Zeolite A and 25 grams of Zeolite Y 110 g of a filler, 3 g of an amine cleaning agent, 2 g of butyl peroxide as a crosslinking agent and 1 g of stearic acid and 5 g of titanium dioxide were added and dispersed to prepare a releasing rubber composition.

<Example 4>

To 100 g of a polymer rubber component containing 80 g of BR and 20 g of EPDM, 45.3 g of a release agent component containing 29 g of PE wax, 11.3 g of amide wax and 5 g of vegetable wax, 20 g of silica A-type and 40 g of silica B- 60 g of the filler, 3 g of the amine cleanser, 2.5 g of butyl peroxide as a crosslinking agent, and 1 g of stearic acid, 1 g of silane, and 5 g of titanium dioxide were added and dispersed to prepare a releasing rubber composition.

&Lt; Example 5 >

To 100 g of a polymer rubber component containing 80 g of BR and 20 g of EPDM, 40 g of a release agent component comprising 25 g of PE wax, 10 g of amide wax and 5 g of vegetable wax, 35 g of silica B-type, 70 g of zeolite A and 25 g of zeolite Y 130 g of the filler, 3 g of the amine cleaning agent, 1 g of butyl peroxide as a crosslinking agent, and additives (1 g of stearic acid, 2 g of silane, and 5 g of titanium dioxide) were added and dispersed to prepare a releasing rubber composition.

&Lt; Comparative Example 1 &

20 g of BR, 20 g of EPDM, and 20 g of a release agent component containing 10 g of amide wax and 10 g of silicone wax, 100 g of inorganic filler containing 25 g of silica A-type, 40 g of silica B-type and 35 g of zeolite A, 3 g of an amine cleaning agent, 2.5 g of butyl peroxide as a crosslinking agent, and 1 g of an additive (silane) were added and dispersed to prepare a rubber composition.

&Lt; Comparative Example 2 &

100 g of a polymer rubber component containing 80 g of BR and 20 g of EPDM was mixed with 100 g of an inorganic filler containing 33.7 g of a release agent component containing 24 g of vegetable wax and 9.7 g of silicone wax, 40 g of silica A-type, 40 g of silica B-type and 35 g of zeolite A , 3 g of an amine cleaning agent, 2.5 g of butyl peroxide as a crosslinking agent, and 1 g of an additive (silane) were added and dispersed to prepare a rubber composition.

The detailed contents of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 1 below.

The maximum torque value and the minimum torque value of the rubber compositions of Examples 1 to 5, Comparative Examples 1 and 2 were measured by ODR (Oscillating Disk Rheometer), and the rubber composition was formed into a sheet shape, At 180 DEG C for 6 minutes at a pressure of 2000 to 2300 PSI. The results are shown in Table 2 below.

Referring to Table 2 above, it was confirmed that Examples 1 to 5 provide a work that does not generate fog and pungent smell when the mold is cleaned using the rubber composition. On the other hand, it was confirmed that Comparative Examples 1 and 2 provide a working environment in which a certain amount of haze and pungent odor are generated. That is, it was confirmed that the occurrence of haze and pungent odor during mold cleaning according to the rubber composition varies depending on the type and composition of the release agent and the inorganic filler. In detail, it was confirmed that a pervious odor occurred strongly in the rubber composition containing the silicone wax, and it was confirmed that the crystalline aluminosilicate in the inorganic filler acts to suppress the generation of odor and haze.

As a result of observing Examples 1 to 5 and Comparative Examples 1 and 2 with respect to mold spreadability, Examples 1 to 5 all included a minimum torque value in the range of 0 to 30 lbf.in, It was confirmed that Comparative Examples 1 and 2 contained a range in which the minimum torque value bypassed 50 lbf.in, and the mold spreadability was remarkably low. That is, it was confirmed that as the minimum torque value indicating the deformation characteristic and minimum viscosity of the rubber composition in the non-cured state was small, the spreadability was excellent and sufficient filling was possible in the mold.

As a result of observing Examples 1 to 5 and Comparative Examples 1 and 2 with respect to mold deformation and mold surface coatability (mold releasability), Examples 1 to 5 showed that the maximum torque value was within the range of 15 to 120 lbf.in Thus, it was confirmed that the rubber composition spreads in the mold to completely cure the rubber composition, and the strength in the cured state is appropriate, and it is confirmed that the rubber composition has excellent mold de-molding and mold surface coating property without shattering. On the other hand, in the case of Comparative Examples 1 and 2, the maximum torque value was shown to bypass 130 lbf.in, and it was confirmed that mold de-molding and mold surface coatability were poor. It was confirmed that when the maximum torque value bypassed 130 lbf.in, the strength of the rubber composition after the hardening during the cleaning process was too high to cause brittleness, and thus, the deformation and the surface coating property of the mold were poor. Therefore, it was confirmed that when the rubber composition had a maximum torque value in the range of 15 to 120 lbf.in, which indicates the strength or shear rate in a fully cured state, the rubber composition exhibited excellent mold deformation and mold surface coatability.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It will be understood that the present invention can be changed.

Claims

Butadiene rubber (BR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene terpolymer rubber (EPT), ethylene-propylene rubber (EPM), ethylene- EPDM), and polyisoprene rubber (NB);
Based on 100 parts by weight of the polymer rubber, 30 to 50 parts by weight of a release agent;
50 to 150 parts by weight of an inorganic filler;
1 to 5 parts by weight of a detergent; And
1 to 10 parts by weight of a crosslinking agent,
Characterized in that the minimum torque value measured by an ODR (Oscillating Disk Rheometer) is 0 to 30 lbf.in and the maximum torque value is 15 to 120 lbf.in.

The method according to claim 1,
Characterized in that the release agent is at least one selected from synthetic wax (FT), polyethylene wax (PE), polytetrafluoroethylene wax (PTFE), combination wax, fatty acid amide wax, vegetable wax, animal wax and mineral wax. This excellent releasable rubber composition.

The method according to claim 1,
Wherein the inorganic filler is at least one selected from the group consisting of silica, silica gel, carbon black, calcium carbonate, calcium silicate, zirconium, iron oxide, activated alumina, aluminum hydroxide, titanium oxide, titanium hydroxide, amorphous aluminosilicate and crystalline aluminosilicate By weight based on the total weight of the rubber composition.

The method according to claim 1,
The crosslinking agent may be selected from the group consisting of dt-butylperoxide, t-buthylcumylperoxide, dicumylperoxide, 2,5-dimethyl-2,5-bis- (2,5-dimethyl-2,5-bis- (t-vutylperoxy) -hexane), and sulfur (sulfer).

The method according to claim 1,
Stearic acid, titanium dioxide, an antioxidant, and silane. &Lt; RTI ID = 0.0 > 18. < / RTI >

6. The method of claim 5,
Wherein the additive is contained in an amount of 1 to 8 parts by weight.